1997 Intrepid cooling problem with 3.5 l V6

On this one with 420 000 km, it started boiling coolant, tried to refill
and bleed it, no luck, runs for a while and then pushes out most of the
antifreeze out through the expansion tank.
So the new motor (used from autowreckers with 130 000 km on it) was
purchased and istalled by them, run for 3 days and started doing the same
thing, overheating and pushing out coolant.
The temperature gauge does not indicate overheating though, but the same
effect, steam comes from under the hood and shortly after the coolant is
pushed out. Both fans are runnning on lo and hi.
When this happen the fans are not evern running sometimes.
Is this a common fault, head gasket, heads or block?
Any info is apreciated.

Ziggie.

 

did they replace the radiator, perhaps it's plugged

Ted

 

Oh, I know what this is. The bottom of the coolant tank rad cap has a
metal plate that sometimes falls off (and usually is laying in the bottom of
the coolant tank) and then allows pressure to blow back out the coolant tank
overflow. I've seen this before on a LHS that was in the shop for a xmisson
job and also happened to be "overheating" as well. We used a stant cap on
it.

Steve m...

 

I just forgot to add, the rad was replaced last winter with the new one,, so
it is not the rad.
But I will look really close at the cap.
I just do not like this cooling system, no pipe from the top, rad too low,
the heater core so high.
This is so weird, how two engines be bad.
On the first engine I pulled the heads, no gasked blown, no cracks seen, put
it together (new head gaskets), could not even bleed air from cooling
system, after I started and wormed it up the coolant was pushed out, it was
not even very hot engine. I assume the engine was bad, (cracked head), as I
did not take the heads for good check (420 000 km) and deceided to get used
engine, as I stated the newer engine run 3 days and stated doing the same
thing.
Would that be someting if the metal plate in the bottom of the expansion
tank was the problem.

Ziggie.

PS.
Thanks for replays.

 

People who installed the second engine took the car back, then they took it
to another shop for diagnostic. I think they went to the dealer with it.
They replaced the thermostat and radiator (recovery/deareation) cap.
The car is on the road again today and so far I did not hear about any
problems.
I think you are right on the money, the cap is most likely the problem.
I did try the thermostat trick on the first engine, but could not totally
bleed the air out (by the bleeder on the thermostate housing), before it
started boiling and pushing coolant out, and I try to do this with cap off
nad on on the tank. But if the cap was bad, could not hold adequate
preassure, that would do.
I will call my buddy right a way and find out how is he doing.

Ziggie

P.S.

Thank for the replays.